Another Loss in the “Untouched” Forest
Photographs highlighting Beech Bark Disease in Cook Forest State Park
Old growth forests are very rare and special ecosystems in Pennsylvania, defined as forests that have reached great age without significant disturbance from humans. These forests are the last remaining glimpse into what Pennsylvania was like before European settlers colonized the land, only 18 such areas remain in the state. However, just because these ecosystems were spared from total destruction at the hands of loggers years ago, they are not out of the woods yet. Invasive species like Beech scale (Cryptococcus fagisuga), Hemlock woolly adelgid (Adelges tsugae), Emerald ash borer (Agrilus planipennis) and Chestnut blight (Cryphonectria parasitica) have been introduced to our old growth forests via human development and are causing widespread destruction throughout eastern hardwood forest ecosystems.
These invasive species are drastically altering natural ecosystems across the eastern US, leading to a biodiversity decrease in even the most protected forests. While some tree species can be selectively protected in our old growth forests (hemlocks from the woolly adelgid) as scientists look for ways to control invasive populations, it is far to costly to save our old growth beech populations from beech bark disease using pesticides. Nearly every beech tree in cook forest state park is either dead or dying, my photos illustrate and spread awareness the widespread die-off in our growth forests.
Cracks in the bark of dead beech trees create eerie textures across the forest.
This tree died earlier than the previous, most of the cracked bark has fallen off.
Here is a dramatic example of fungus overtaking a younger beech. The damage caused by invasive beech scale insect feeding opens the door for all kinds of fungi to prey upon the now vulnerable tree. Nectria Coccinea Var. Faginata is one of the pathogens typically associated with BBD but, as seen in this photograph, other fungal species take advantage of host trees as well.
The cankers and flaky bark all the way up the bole of an older beech are characteristic of a badly infected tree. In this photograph you can also see where a large limb has broken off. As the dead trees degrade they are susceptible to beech snap, when the tree snaps above head height, creating dangerous circumstances for people below on windy days enjoying the forest.
This image shows the tangled mess of dead stumpy beech limbs in the forest canopy. This is a common sight as the dead trees begin falling apart.
This beech is not yet dead, however it is growing many small branches all along the bole as a last ditch effort of survival. Fungi will likely take over and kill the tree sooner than later. The orange leaves are a hallmark of beech trees throughout the winter time as the species commonly displays marcescence.
Another fungus growing out of a dead beech.
This image shows how widespread this destruction is throughout the forest. These two trees have been killed by BBD and are now falling apart together.
This part of a fallen beech limb almost seems to look like a face. Framed by two hemlocks that were missed by the falling limb.
Mushroom growing out of the base of a beech tree.
Dead limbs criss-crossing the forest are a common sight as the beech population dies throughout the ecosystem.
Another fallen limb leaning on some hemlocks with more dead beech seen standing in the upper left background.
Some larger beech trees, killed by BBD, are caught by old growth white pine and hemlock. A younger beech in the foreground is also fungus infested due to the beech scale.
The interesting root system of a sickly beech.
There is some good news…
As this species eliminating epidemic spreads across the US, it has been realized that about 1% of the beech population is naturally resistant to beech scale infestation. This very small percentage of the population is being used by some scientists to selectively breed beech populations that are much less prone to being destroyed by the invasive insect and its fungal partners. This gives me hope that we will not see the total near permanent wipe out of American Beech across the US, like the fate suffered by our American Chestnuts. Hopefully these selectively bred beech trees will be reintroduced into forests where the killing front of BBD has passed through to help restore our natural biodiversity. Even if this reintroduction is not done across the entire natural range of American Beech, I think it should be a priority to reinstate resistant trees in affected old growth forests throughout PA and the northeast in order to preserve the natural heritage of these ecosystems.
The other beech problem…
There is another disease starting to affect beech trees throughout the eastern US known as beech leaf disease. This problem has been discovered much more recently than BBD and poses another threat to our already crippled beech populations. Beech leaf disease has been seen to prey upon younger trees more severely then older trees which could become an issue for reinstatement of beech in BBD affected forests. The exact ecological cause of BLD is not yet known but scientists are making promising leads in regards to understanding this new problem fully.
All in all…
The eastern US is suffering a large scale loss of an important species due to human induced invasive species. Not many know about this issue, so I am here to document it and spread awareness of this problem especially with respect to Pennsylvania’s old growth forest ecosystems. Introduced diseases like this are only becoming more common throughout the country and will continue to wreak havoc to native tree species in the US. First the chestnuts, then the ash, and now the beech. Hemlock populations are also in severe danger across PA, but in cook forest and other old growth ecosystems it is possible to keep populations alive with chemical treatment. (Scientists are looking at ways to save our hemlock populations by fighting the invasive woolly adelgid with other introduced insects that prey on woolly adelgids while not harming the ecosystem.) These issues are deepening the divide between us and our natural heritage, so I think it is important that more people know about the state of our forests and hopefully gain more respect for the ecosystems we inhabit.
Resources:
Dr. Kimberly Bohn’s presentation describing the progression of the “aftermath forest” following beech bark disease infestations. Presented March 21, 2018 by Dr. Kimberly Bohn, Penn State University Cooperative Extension. https://www.youtube.com/watch?v=P24c9oE5Vvg
MAJOR NEW TREE DISEASE EPIDEMICS: BEECH BARK DISEASE D. R. Houston, Annual Review of Phytopathology199432:1,75-87
Sharon E. Reed, Daniel Volk, Danielle K.H. Martin, Constance E. Hausman, Tom Macy, Tim Tomon, Stella Cousins, The distribution of beech leaf disease and the causal agents of beech bark disease (Cryptoccocus fagisuga, Neonectria faginata, N. ditissima) in forests surrounding Lake Erie and future implications, Forest Ecology and Management, Volume 503
https://www.oldgrowthforest.net/pennsylvania
Natalie R. Pinheiro, P. Charles Goebel, David m. Hix; Forty-two years of change in an old-growth and second-growth beech-maple forest of north central Ohio
William H. McWilliams, Carol A. Alerich, Daniel A. Devlin, Andrew J. Lister, Tonya W. Lister, Stephen L. Sterner, James A. Westfall; Annual Inventory Report
for Pennsylvania’s Forests: Results from the First Three Years
Dale J. Luthringer, Environmental Education Specialist, Cook Forest State Park